二、故障分析(电路图见上期) 1.色度通道故障当色度通道发生故障时。屏幕上往往只有黑白图像而无彩色。如副载波振荡器停振、PAL开关动作不正确等,均会使ACK消色电路动作,从而造成图像无彩色故障。如: ①X_(SOI)失效使4.43MHz副载波振荡器停振,同步 Second, the failure analysis (circuit see last issue) 1. Chroma channel failure Chroma channel failure. The screen is often only black and white images without color. If the subcarrier oscillator is stopped and the PAL switch is not operated correctly, it will make the ACK achromatic circuit operate, resulting in no color fault in the image. Such as: ① X_ (SOI) failure 4.43MHz subcarrier oscillator stop vibration, synchronization